Search results for "LOAD"

The collaborative consistent vehicle routing problem with workload balance

2021

Abstract The rising competition in the logistics sector forces companies to be more economically efficient. One of the major sources of inefficiency is the incomplete usage of available resources, such as vehicles’ capacities. Mechanism that allow to better exploit such resources by enabling carrier collaborations are on the rise. Our study examines a centrally organized multi-period collaborative vehicle routing problem, where carriers can exchange customers who have to be serviced on a regular basis. Collaborations, where carriers serve frequent customers, are supposed to face the problem of (i) time consistency in terms of visiting time, and of (ii) service consistency. The latter ensure…

Editorial issue 2

2018

It has been a very long trip since I wrote my last editorial. The first issue of the Journal received a strong welcome from all over the world in the beginning of 2016, but there was something missing that drove us to a winding road that ended in an even stronger situation: the support of the University of Valencia’s Publication Service (UVPS). The missing thing in the first issue was the DOI (Digital Object Identifier). All the online journals have a DOI to identify the papers and allow a permanent link to them. Each DOI is unique for each paper. We look for a DOI provider in our environment and found the UVPS to offer DOIs for free to their teachers. As I am one of them, I went to ask for…

Vehicle scheduling for rental-with-driver services

2021

Abstract In this paper, we introduce a new vehicle scheduling problem (VSP) with driver consistency faced by rental-with-driver companies. A weekly time-horizon is considered and a set of potential customers, each one associated with a list of required tasks, is assumed. The company can choose to accept or reject a customer, but if accepted, all required tasks must be performed by the same driver. A profit is associated with each customer. The goal is to maximize the company’s total profit, by respecting a list of daily and the weekly drivers’ workload limitations imposed by drivers’ contracts. We propose a mathematical formulation of the problem and design an exact solution method based on…

Transportation Services as Specific Logistics Projects for Oversized Cargo in Poland

2016

Market observation demonstrates that the transportation-freight forwarding-logistics sector carries out diverse projects based on clients’ orders. The majority of those orders are unique and project related. Recently, the project approach to logistics has gained significance. Logistics project management is a relatively new area of knowledge about logistics and supply chains. The paper presents the essence and characteristics of transportation services as a specific logistics project. The authors characterize the transportation-freight forwarding-logistics sector, with particular focus on the sector of oversized cargo transportation. The demand for such services depends on the industry, ene…

EV-planning: Electric vehicle itinerary planning

2014

International audience; In the latest few years, lot of efforts have been done to pave the way to sustainable mobility, in order to solve pollution problems and fuel shortage. The use of electric vehicles (EV) is considered as one of the best ecologic and economic solution. However, autonomy barriers and limitations slow the progress and the deployment of this technology. In this paper, we propose an advanced electric vehicles' fleet management architecture. This architecture considers the most important factors that can affect the traveling mode of electric vehicles, in order to offer different services to fleet management companies for an efficient monitoring and management of their fleet…

Skilled workforce scheduling in Service Centres

2009

Abstract The Skilled Workforce Project Scheduling Problem (SWPSP) is a complex problem of task scheduling and resource assignment that comes up in the daily management of many company Service Centres (SC). The SWPSP considers many real characteristics faced daily by the SC: client-company service quality agreements that establish maximum dates for the beginning and the end of tasks with penalties for delays, criticality levels indicating the client-priority in processing each task, generalized precedence relationships that can produce cycle structures, time period and percentage time lags and variable task durations depending on the worker executing the task. Furthermore, the SC workforce i…

EVALUATION OF BACTERIAL AND FUNGAL LOAD IN FRESH, FROZEN AND DRIED FOOD MUSHROOMS

2015

The analysis carried out by Doores et al. (1) and Venturini et al. (2) on the total bacterial load tested in wild and cultivated fresh mushrooms highlight values ranging between 3.7 and 9.3 log ufc/g. Due to the absence of pathogens, the microbiological quality of mushrooms analysed by the above-mentioned authors has been considered good. On the basis of data reported in literature we have also extended the observations with frozen and dried mushrooms in order to evaluate the mesophilous bacterial and fungal load. In particular the presence/absence of Escherichia coli (Migula,1895) Castellani & Chalmers, 1919, Salmonella spp. and Listeria monocytogenes (Murray et al.1926) Pirie 1940 was…

The influence of substitution in the quinoxaline nucleus on 1,3-dipolar cycloaddition reactions

2013

The reaction mechanism of 1,3-dipolar cycloadditions of both symmetric and unsymmetric benzo-condensed diazines with a nitrilimine dipole, to give two different mono- and bis-cycloadducts, in tetrahydrofuran (THF) solution, was studied by DFT calculatio ns. The results obtained show that each 1,3-dipolar cycloaddition reaction always proceeds by a two steps mechanism, in which the first intermediate shows only one covalent bond between the beta carbon of the nitrilimine and the aromatic nitrogen of the diazine molecule. The structure and energy content of the two transition states of the two cycloaddition steps, in the case of the unsymmetric benzo-condensed diazine, nicely explains why the…

SINTESI DI ANALOGHI DI ACIDI NUCLEICI PEPTIDICI CICLICI ATTRAVERSO REAZIONI DI CICLOADDIZIONE 1,3-DIPOLARE

2012

Integrated production of biopolymers with industrial wastewater treatment: Effects of OLR on process yields, biopolymers characteristics and mixed mi…

2022

The production of polyhydroxyalkanoates (PHA) using industrial wastewaters as feedstocks is a current and challenging topic. This study investigated the production of biopolymers by a mixed microbial culture under different OLRs equal to 1 kgCOD m-3d-1 (Period 1), 2 kgCOD m-3d-1 (Period 2) and 3 kgCOD m-3d-1 (Period 3). The maximum PHA content was achieved in Period 2 (0.38 gPHA gTSS-1), whereas lower values were obtained in Period 1 (0.13 gPHA gTSS-1) and Period 3 (0.26 gPHA gTSS-1). Overall, the maximum PHA productivity resulted equal to 0.08 gPHA L-1h-1 (P2), 0.05 gPHA L-1h-1 (P1) and 0.04 gPHA L-1h-1 (P3), respectively. The molecular weight of the PHA increased from Period 1 (250 kDa) t…